This invention relates to an adjustable apparatus for indicating the position of a mechanism, such as the position of a valve plug within a valve.
There are numerous applications for an apparatus which provides an indication of the position of a mechanism operable between two or more positions. In the process control field, for example, valves are commonly used to control the flow of fluids, and operators, often located in a control room remote from the valves, must be able to quickly determine the status of a particular valve, e.g., whether it is open or closed. Accordingly, it is also common to provide apparatus resident with the valve, typically with the valve actuator, for monitoring the status of the valve and means for conveying this information to the control room. There, the operator can monitor the position of the valve at a control console or by observing indicator lights on a control panel.
Although such apparatus has been provided in the past, one shortcoming is that they have not been easily adjustable to accommodate different types of valves or variations in the travel of the valve plug required to open and close them. Such differences and variations have frequently required extensive modifications or complicated calibration of the apparatus.
It is a general object of the present invention to provide improved apparatus which avoids the above problems and is readily adjustable.